Simulating a one-dimensional plasma

A plasma is an ionized gas in which some of the electrons are free rather than bound to atoms as in an ordinary gas. The behavior of a plasma is more subtle than the behavior of an ordinary gas. In an ordinary gas the dynamics is dominated by two-body collisions, but in a plasma the particles interact via long-range forces, and this interaction causes the plasma to exhibit collective effects. In this paper we describe a dynamical model of a one-dimensional plasma and present a simple algorithm for simulating the model on a computer. We use computer simulations to illustrate two of the most important collective effects in plasma physics: Debye screening and plasma oscillations. This paper provides an introduction to plasma physics that should be accessible to undergraduates, and can be used to supplement undergraduatelevel courses on plasma physics, statistical mechanics, or numerical modeling.